Trying to vote on a poll using the Polls link fails

[#1]

If I try and vote in the poll using the Polls link in the header rather than the poll in the sidebar, I get a message telling me to select a valid entry. Using the poll in the sidebar works fine.

[#2]

Yep.  I've seen that one.

[#3]

Added as bug.

[#4]

You shouldn't, according to the documentation, be able to vote from the polls link in the header.
Investigation needed.

[#5]

Fixed.